1. Field of the Invention
The invention relates to information processing techniques. More particularly, it relates to a circuit or device which steps in at the level of reading devices of memory systems, whether central working memories or microprogrammed control memories of computer are concerned, to reduce access time to information contained in the memory system.
2. Description of the Prior Art
The set of operations necessary for extracting an item of information from a memory system takes place sequentially in time and forms part of what is called the "reading cycle" of the memory system. The accepted technique for collecting information issuing from a memory group or assembly utilizes a register located at the output of the memory group. This register, known as a data or an instruction register, is either of the clock-equipped or locking type. In the first case, the input information issuing from the memory system enters the register in response to the appearance of a clock signal. In the second case, the input information of the register passes through it and is frozen in the logical state that it presents at the instant when a locking command signal is rendered operative.
One of the more important parameters which characterizes the performance of a memory system is its access time. This is the time which elapses between the presentation to the memory group of the so-called addressing signals which define the memory zone consulted and the information signals issuing from this storage or memory group being made available to the processor. In the usual arrangement, however, this access time is manifestly affected by the presence of an output register, called the information register, designed to collect the output signals of the memory group. In face, the output signals are fleeting in comparison with the duration of use generally required by the processor. Either the storage devices naturally offer signals of limited duration, or else their maintenance is subject to the control of a command signal the duration of which is itself limited either for technological reasons or in order to link up other operations more rapidly.
The object of the invention is therefore to reduce the access time and, consequently, improve it by taking the information register out of the chain of elements arranged in cascade between the addressing signals at the input of the memory system of an information processing system and the information signals derived at the output of the memory system.